Northwest table grapes

A Willamette Valley nurseryman is seeking varieties suitable for Oregon and Washington.

Aug 1, 2007

Ray Ethell, left, and OVS crop consultant Jeff Flake discuss the open-gable trellis system, on which grape clusters are more exposed for easier thinning and harvesting.

There’s more to the Oregon viticulture industry these days than what ends up in a premium wine bottle.

At a small nursery in the mid-Willamette Valley, a former Oregon State University small fruits technician is betting the farm that seedless table grapes can become a viable crop in western Oregon and Washington.

Ray Ethell, owner-operator of Broadacres Nursery near Hubbard, began experimenting with table grapes in 2003 with a number of cultivars obtained from various sources, both public and private.

All of the vines he works with are virus-free and omega bench grafted at the nursery onto rootstocks that are resistant to crown gall and phylloxera.

The mother block takes up about 1.5 acres and includes some 35 varieties of red, green, and blue grapes.

Ethell, who also propagates wine grape plants, believes table grapes are a good fit in this part of the country. "I’ve always wanted to do table grapes and think western Oregon and western Washington are best suited for them."

Twenty years earlier, he recalled, someone had tried growing table grapes in northeastern Oregon, around Hermiston, but the crop was lost to frost. "I said they have a good idea, but they’re in the wrong place."

West of the Cascades, the harvest window for the varieties Ethell is experimenting with runs from the middle of September to the middle of October, which is after California shuts down and before Chile starts up. Most of the varieties hold up well in cold storage for 60 days, he said. "Then you end up battling fruit rot, Botrytis, and all sorts of cooler issues."

At first, interest in Ethell’s little project was slow in coming, but towards the end of the three open houses he held last year, orders began to pick up. About 20 percent of those attending were commercial growers.

"The first weekend was a little discouraging," he related. "We only had about 25 people. The next weekend, it picked up to about 35 people, still disappointing. And the third weekend, it jumped up to 65 people, and we’re as busy as all get-out."

Since then, orders have been trickling in on a regular basis, he said. "Some people want two or three plants, some want a couple of hundred."

Ethell established the table grape evaluation plot three years ago. His aim is to come up with ten or so varieties that are best suited for the Willamette Valley. He’s evaluating yields as well as flavor profiles. So far, several varieties, such as Red Flame, the variety found most often in grocery stores, and the purple Jupiter, have jumped out as excellent candidates.

Ethell sees his mother block continuing to serve as an outdoor laboratory. "I hope it continues that way. We’re always learning new stuff. When we discover new issues we have a place to try them out so growers don’t have to make the same mistakes over and over." This year, he will experiment with cluster thinning and trimming to produce larger grapes.

Open gable

Last year, Ethell made a dramatic change in his tiny vineyard by installing a new trellis system—the open gable popular in California—that he says will ripen fruit better. In contrast to the traditional two-wire curtain system used by wine grape growers, the open gable system has a "Y" trellis format with six horizontal wires, three on each branch of the "Y."

Last year, which was the second year for the evaluation block, the two-wire curtain system worked fine, but he didn’t have a full crop. Now that he has a full crop, the weight of the fruit is too heavy for that system, and the canes and fruit would flop over in the wind and rain.

Jeff Flake, crop consultant with OVS (Orchard Vineyard Supply) in Aurora, Oregon, said that while wine grapes, especially Pinot Noir, are cropped at around two tons per acre, table grapes yield up to six or eight tons. He retrofitted several rows of table grapes in Ethell’s one-acre experimental block with the open-gable system, which is designed to carry more weight.

Because table grapes crop so heavily, labor, which is all done by hand, becomes a critical issue, Ethell said. On the open gable, grape clusters are much more exposed and higher up for easier thinning and quicker harvest, while management of the fruit is easier and more efficient. The open-gable trellis system also allows Ethell to apply fungicide sprays more efficiently since there’s no "shield" of foliage to block the spray from getting to the grape clusters.

The wires on the open-gable system are adjustable so that the vine canopy can be opened up to allow more air and sunlight to reach the plants. "It gives you a lot of flexibility in managing the canopy," Flake said.

Different table grape varieties require different degrees of openness in the canopy, Flake explained. "Sometimes, they like to tuck the green varieties further into the shade and leave a full canopy so that they don’t sunburn."

The architecture of the open gable system also allows easy placement of poly covers for rain and bird protection.

Ethell is also conducting an irrigation trial this year. "We had a little bit of an issue with Red Flame splitting last year. So, I have a trial where half the row is irrigated and the other half isn’t."

Marketing

While Ethell sees many of the grafted and self-rooted vines he sells ending up in backyards, he believes the crop can reach the critical mass needed for marketing to large grocery stores.

"In the retail sector, where most table grapes go, people want larger berries and pretty-looking clusters. Part of our job here is to find those selections."

If nothing else, table grapes should do well at the numerous farm stands in the valley in late summer and, thanks to cold storage, be available into late October when pumpkins become popular.

For the third year in a row, Ethell will hold open houses on September 8, 15, and 22, so that interested growers, both commercial and home-use, can study his experimental vineyard and taste the different varieties of table grapes.